black stripe along left edge of paper

i have an HP laserjet 4si and every time i print something there is a black stripe along the edge of the page. i read in another thread to print something and stop it before it comes out. i did that and the stripe was already present before the fusing asembally. (that is if the fusing assembally is that black thing that says caution: 8 zillion degrees. and when i touched the paper toner wiped off onto my finger so i'm guessing im right.) they said that if this is the case, it is proabaly bad toner but i replaced the cartridge and the problem is still there. any ideas? i'm starting to get pissed off using my inkjet for text and wasting $$ on ink.

im not sure if this is significgant or not but when i opened the cartridge it was from when i stopped it in the middle. it had the stuff it was about to print in mirror image on it. this stripe was also on it.

A defective laser scanner will not generate vertical black stripes. Horizontal ones, yes. If the stripe is on the cartridge drum, then the only thing it could be is a defective toner cartridge. There is a drum wiper blade that is responsible for cleaning the drum. No matter what else is going on, it should clean the drum of all residual toner before a new image is put on it. You can remove the cartridge and manually turn the drum with your right thumb. Turn it away from your body. A good wiper blade will clean the stripe off. Was the replacement cartridge new or a remanufactured one?

A black stripe could be caused by something blocking the path of the laser between the scanner assembly and drum. I know it's a different printer, but had a simmilar problem with a Brother HL-1240, the cleaning tab in the drum assembly was placed on the wrong side.

Suggest that the owner of the printer in question looks for anything in laser path or damage to left hand side of transferr roller.